Device for generating a warning signal, especially for helicopters

ABSTRACT

The present invention relates to a warning device for indicating dangerous circumstances, especially for helicopters, having a signal receiving means for receiving and processing an operational status signal; a signal comparison means which compares the received operational status signal against predefined criterion; a monitoring signal generating means which generates a monitoring signal when the operational status signal meets said criterion; a monitoring transmission signal transmitting means which wirelessly emits said generated monitoring signal; a monitoring transmission signal receiving means which receives said emitted monitoring signal; a monitoring transmission signal comparison means which analyzes whether said received monitoring transmission signal meets predefined monitoring transmission signal criteria; and an output means which emits an output signal when the monitoring transmission signal meets said criteria, whereby said receiving means, said monitoring transmission signal comparison means and said output means are worn by a user and said output signal is immediately perceived by the user.

BACKGROUND OF THE INVENTION

The present invention relates to a method and a device for thegenerating of a warning signal, especially for helicopter pilots.

The present invention will be described in the following primarily usingthe exclusive example of generating a warning signal for helicopterpilots.

It is however to be pointed out that this description on the use of thepresent invention in no way restricts its use in other similar areas,but rather that it is also possible to make use of the present inventionin conjunction with other technical devices and configurations, such asfor example other aircraft and flight devices in general, as well asmotor vehicles, trucks, and also when operating and monitoring suchmachines, plants and systems in which an operator needs to beimmediately and reliably alerted about a dangerous situation which canarise suddenly.

The powering of a helicopter usually transpires with an internalcombustion engine, for example a turbine, its output coupled to therotor blades via a transmission.

Since rotor drive failure must be avoided at all costs, it is necessaryto constantly monitor the operating status of an internal combustionengine (turbine) and transmission. The pilot must hereby pay particularattention to ensuring that the turbine's running temperature does notexceed a predefined critical limit and furthermore that neither doestransmission torque exceed a predefined critical limit.

Even just a slight overloading of the transmission, meaning for exampleexceeding the maximum permissible torque by 10 to 15%, necessitates acostly overhaul of the transmission.

In large helicopters, the pilot's collective pitch lever, referred to ascontrol stick in the following, is outfitted with a device, as is alsocustomary for example with the control yoke in commercial airliners,which serves to alert the pilot to dangerous circumstances. Said deviceinduces the control stick to initially vibrate slightly when the pilotis approaching a dangerous condition, and then to shake more stronglyupon reaching an inadmissible state.

Such vibration mechanisms however are very costly which prohibits theiruse, especially in smaller flight devices. In addition, they require aconsiderable amount of space and are themselves subject to extremelystrict safety requirements since a vibration mechanism must never inducea faulty functioning of the control stick.

It is the task of the present invention to provide a method and a devicefor the generating of a warning signal, especially for helicopterpilots, which can be easily and inexpensively installed or integrated ina helicopter, an airplane, a motor vehicle or any system to bemonitored, and which is furthermore suitable for being retrofitted.

SUMMARY OF THE INVENTION

This task is solved in accordance with the present invention by a deviceaccording to claim 1.

Preferred embodiments of the invention constitute the subject matter ofthe subclaims.

The present invention has considerable advantages compared to knownwarning systems.

Electrical sensors are employed to detect parameters to be monitored,such as for example, operating temperature and transmission torque. Theoutput signals from these sensors serve as comparative signals. In manycases, there may even be a status alarm signal already provided inmeasurement processing systems of the corresponding mechanism; e.g., thehelicopter. This then further reduces efforts expended in signaldetection and processing. Utilizing existing sensors enablesparticularly simple and economical retrofitting of existing helicoptersand similar contrivances.

A relatively compact small electronic device is required for theprocessing and emitting of such signals. It must be able to beaccommodated easily into smaller aircraft, etc., Similarly, thereceiving device can also be configured as a small compact device to beworn by the pilot and which remains in constant contact with thetransmitting device by means of a wireless connection.

This system provides for an overall company warning device which in noway affects the operation of the associated mechanism, but which is ableto indicate a dangerous situation in a very reliable manner.

Compared to control stick vibration devices, the investment expenditureis considerably less.

Since the warning device has no mechanical connection to the controlstick nor to any other component of the airplane, there is no danger ofthe device adversely affecting any of the functions.

According to a preferred embodiment, the warning device is worn on thewrist like a wristwatch. Signaling preferably ensues by having thedevice vibrate when a state of alarm is detected, thus alerting thepilot of the dangerous situation. Alternatively, other mechanisms mayalso be used to indicate alarm status, for example, heating up to acertain temperature limit which is physiologically not harmful to theskin, the emitting of a small, physiologically harmless electricalpulse, etc.

A configuration of this type has numerous advantages.

During the course of performing his duties, a helicopter pilot is oftenvisually and/or acoustically distracted to a great degree. For example,a pilot who is maneuvering a complicated take off or landing in tightquarters has no time to simultaneously pay close attention to hisinstrumentation. The same applies when, for example, the pilot of atransport helicopter has to set down loads such as, for example, columnsfor power lines, ski-lifts and the like, maneuvers which requireabsolute pinpoint accuracy. Although transport helicopters have, forexample, their own indicator instruments for turbine temperature andgear torque located outside of the helicopter so that pilots lookingdownward can still monitor their instruments, this type of additionalinstrumentation is not only very expensive, it can also interfere with:the pilot's field of vision while performing such tasks.

The warning device according to the present invention ensures that thepilot continues to be kept informed even when he is deeply concentratedon other tasks.

A warning device of the inventive type is superior to audible warningdevices such as, for example, a horn or the like. Especially whileperforming difficult tasks, a pilot is acoustically distracted byconversations with the control tower or with members of his respectivework team or rescue troop and may therefore, not always perceive such asignal.

A device with a vibration mechanism or a similar warning mechanism doesnot require any attention on the part of the pilot, nor does it distracthim from fulfilling his relevant duties. The pilot can, therefore, fullyconcentrate on the actual task at hand.

Apart from these considerations, there is however an embodiment of thepresent invention which also involves a visual signal.

In said embodiment of the invention, the receiver, or at least anoptical display means coupled to the receiver, is integrated into a pairof glasses, for example sunglasses. This display means is well-suited tokeeping the pilot informed of dangerous situations or of his measurementreadings without the need for additional instruments and withoutnarrowing his field of vision.

In a first embodiment, the glasses are configured such that one or twowarning lights, preferably LEDs or the like, are activated in adangerous situation. In such a state of alarm, the pilot will then see,for example, corresponding red warning lights lighting up on the upperframe of his glasses, thus becoming alerted to dangerous circumstances.Such a device is a very reliable warning device since the glasses are ofcourse always within the pilot's field of vision and hence it is alsopossible to warn a pilot even when he is not looking directly at hisinstruments. Furthermore, the lighting up of a warning light in theglasses is a very clear visible signal that will not be overlooked bythe pilot even during dangerous situations. In order to increase itsvisibility, the signal can also be made to flash.

Besides having just a warning function, an instrument configured in thisway can also assume other functions. Hence, it is particularly possibleto alert the pilot not only to the actual danger itself, but also to animpending danger.

When employing a warning light, the light can start to flash at a slowrate when, for example, a pilot comes within a certain percentage of acritical value; e.g., 10% or 20%. He is thus made aware of approaching adangerous situation. The closer the corresponding reading comes to thecritical threshold limit, the higher the flash frequency will be, sothat by noting the frequency of the flashes, the pilot flying thehelicopter remains informed about his permissible range while alsosimultaneously concentrating on other duties.

Instead of using a flash frequency, other measures are also possible.For example, a color display can be utilized which for instancegradually changes from green to red to show the approaching of dangerousstatus. It is furthermore possible to indicate an impending dangerouscondition by, for example, a variable number of activated light sources.A first lighted or flashing LED would thus indicate the approaching ofdangerous status and the closer the aircraft continues to near saiddangerous situation, the more LEDs are switched on up to a maximum of,for example, five LEDs.

As previously cited, it is preferred to utilize LEDs, LCDs or other suchsimilar indicators for the display.

In a further variation of this embodiment, the receiver and the alarmoutput means are arranged in the housing of a wristwatch. Upon theoutputting of an alarm, the contacts which are disposed on the undersideof the housing and which are in contact with the user's skin, emit smallharmless electrical pulses that are registered by the user.

DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

Further advantages, features and application possibilities of thepresent invention will now be specified in the following description ofan embodiment in conjunction with the figures, which show:

FIG. 1 a schematic functional representation of a warning device in anembodiment of said warning device according to the present invention;

FIG. 2 a schematic representation of the transmitter unit of theembodiment according to FIG. 1;

FIG. 3 a schematic representation of the functional modes of thetransmitter unit of the embodiment according to FIG. 1;

FIG. 4 a schematic representation of the coding of the transmissionssignal of the embodiment according to FIG. 1;

FIG. 5 a schematic representation of the configuration of thetransmission signal during normal operation in the embodiment accordingto FIG. 1;

FIG. 6 a schematic representation of the configuration of thetransmission signal during address change mode in the embodimentaccording to FIG. 1;

FIG. 7 a schematic representation of the receiver unit of the embodimentaccording to FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

The first embodiment of the invention explained with reference to FIGS.1 to 7 is designed for monitoring transmission torque in a helicopterand emitting a warning signal when the gear torque reaches a criticalvalue. However, wherever applicable, same can also be used to monitorturbine temperature in a helicopter or for other technical devices andconfigurations, such as airplanes and flight devices in general, or inmotor vehicles, trucks, machines and other kinds of systems.

FIG. 1 shows a highly schematic representation of the warning device,which is indicated as a whole by reference numeral 1, and having atransmitter unit 2 comprising the transmitting device and a receiverunit 3 comprising the receiving device.

In the present example, transmitter unit 2 is fixedly mounted in thehelicopter's cockpit (not shown in the figures).

A torque sensor 7 is arranged on the transmission to record gear torque.

During operation, receiver unit 3 is employed while at spatial distancefrom transmitter unit 2 and is coupled to display means 4 and warningmeans 5, both customarily incorporated directly into the housing of thereceiver unit.

The schematically represented transmitter unit 2 in FIG. 2 has a housing10 in which the electrical and electronic components of the transmitterunit are arranged.

Housing 10 additionally accommodates a battery 13 which supplieselectrical power to the receiver unit. In an embodiment not representedherein, the transmitter unit is supplied with electrical power from thehelicopter's power supply means.

The configuration of the transmitter unit's electrical components willnow be described with reference to FIG. 2.

Torque sensor 7 is connected with a signal processing circuit 20 viaelectrical conduit (here and in the following always depicted onlyschematically). All types of sensors as commercially available may bereadily used as a torque sensor.

The torque sensor's analog signal is converted into a digital signal byan A/D converter in signal processing circuit 20. Signal processingcircuit 20 is further connected to a quartz-driven timer 21, the purposethereof to be explained in the following. The digitally processed signalis fed to a conventional microprocessor CPU 22.

Microprocessor CPU 22 is linked to a memory 23 and likewise receives thesignals of timer 31. Memory 23 (and the corresponding memory in thereceiver unit) can be rendered wholly of RAM memory elements. It ishowever also possible to make use of a mixed memory consisting of ROM(constant memory) and RAM memory elements. Since a stable continuousvoltage is provided by the battery, the contents of the memory are savedlong-term, even when working with volatile memory elements.

Microprocessor 22 converts the load signal as well as any other signalsto be transmitted into a transmission signal according to a programstored in memory 23 and feeds same to a transmission output stage 25.From transmission output stage 25, the signal is transmitted to antenna26 which is made of a ferrite core wound in copper wire.

Different methods for operating the transmitting device will now bedescribed with reference to FIG. 3 in which the various functional modesof the transmitter unit are plotted across time axis 40.

In the time segment 41 shown on the left side of the figure, thetransmitting device is in, stand-by mode.

When the helicopter is first started, the transmitting device switchesfrom stand-by mode to transmitting mode. Right after being switched on,a so-called address change mode or pairing mode initially ensues in timesegment 43; this will be clarified at a later point.

The actual normal mode of time segment 45, which represents the actualoperational phase of the shown device, follows the address change mode.As is schematically depicted in FIG. 3, this mode alternates between ameasurement interval 46 and a transmission interval 47. After eachmeasurement value has been received, the microprocessor then generatesthe transmission signal and conveys same to antenna 26 via transmissionoutput stage 25.

The signal to start the torque measurement is given by timer 21 of thetransmitting device. Microprocessor 22 is thereupon activated and thetorque is measured via torque sensor 7.

The interval of time transpiring between the measuring of the torque andthe emitting of the signal is not constant, but rather varied by themicroprocessor within a predefined range of time according to a randomprocess.

Emitting of the signal however always transpires before the receipt ofthe next measured value. This temporal variation has the advantage thatin the instance of two warning devices which are simultaneouslymonitoring different helicopters at a close distance to one another,emitted signal values will only collide randomly.

If the time span between the measurement interval and transmissioninterval was always the same, this could lead to an unfortunatearrangement wherein the values emitted by two transmitter units wouldcollide with one another over a longer period of time.

As soon as the helicopter is switched off, the transmitter unit switchesback to stand-by mode, as shown in time segment 49.

The transmission of the signal from transmitter unit 2 to receiving unit3 ensues via electromagnetic radio wave at constant frequency. Astandard quartz-driven timer 21 serves to control the transmissionfrequency.

The data signals to be transmitted are digitally encoded in transmitterunit 2 in order to lessen susceptibility to interference for the datatransmission. There are various methods known in the prior art fortransmitting digital data in which the carrier frequency, amplitude orphasing can be modified.

A known method which can also be employed for a warning device of thetype as depicted here is changing of the transmission signal frequencyutilizing the so-called “frequency shift keying” process. In thismethod, the “0” and “1” bit information data are allocated differentfrequencies which, however, means that two frequencies must betransmitted, increasing the efforts expended at both transmission andreceiving ends.

The best transmission prospect has proven to be the manipulating of thephasing making use of the so-called “phase shift keying” (PSK). In thepresent embodiment, another particular variation of the PSK method isemployed, namely a “differential phase shift keying” (DPSK).

In this method, the transmission signal undergoes a phase jump upon a“1” being transmitted; upon a “0” being transmitted, the transmissionsignal remains unchanged. As the first bit of the transmitted binarypattern in this method contains an uncertainty, it cannot serve as acarrier of information.

An example of this digital encoding is represented in FIG. 4. Diagram 60depicts a binary pattern constituting the bits 011010011 . . . plottedacross a time axis 61 and a numerical axis 62.

In diagram 64, a voltage signal 67 is plotted across the same scaledtime axis 65 and a voltage axis 66, which exhibits a constant frequency,however in which the binary pattern is cast as phase shift by means ofthe afore-described DPSK modulation.

It is evident from FIG. 5 that a sequence of signals is emitted withineach transmission interval, said sequence comprised of a preamble, theaddress signal, a data block and a postamble.

The preamble serves to enable synchronization of the receiver device tothe signal sent. The address signal contains the specific transmitteridentification, followed by the actual data block to be transmitted. Theblock of data in all cases contains the measured torque but, in apreferred embodiment, it can certainly also include a temperature value,to be detected by a corresponding temperature sensor.

Of course other data can also be transmitted as well, when same would beof interest for specific applications. Finally the postamble follows,serving among other things as an error corrector.

In the embodiment as represented, the synchronization interval comprises16 bits, the address signal is of 24 bits, the data block is 32 bits,and the postamble is 4 bits, resulting in the signal being 76 bits longin total.

The configuration of the receiver unit will now be described withreference to FIG. 7.

Receiver unit 3, being separate from the transmitter unit, isaccommodated in a housing 70 and has no physical connection whatsoeverto transmitter unit 2, be it in mechanical fashion or via electricalconduits. Housing 70 contains a battery 71 in order to provide power tothe electrical and electronic components.

A flexible strap (not shown) is furthermore disposed on housing 70,enabling the user to fasten the receiver unit at his wrist like awristwatch.

In order to start operation of the device and to confirm the allocationin the pairing mode, a acknowledgement switch 73 is recessed into thehousing so that the user can actuate said switch, for example, with afinger. Under certain circumstances, this action is then interpreted bythe receiver unit as a switch event.

The receiver unit also has a ferrite antenna 80, as representedschematically in the figure. The received signal is initially fed to asignal processing and amplifying stage 81, followed by a digitalizationstage 82. Both of these components correspond to the conventionaldesign.

The digital signal is fed to a comparator 83 which determines whetherthe received and processed signal contains the address signal or theaddress control signal. Should this be the case, the signal is fed tomicroprocessor 85, which is controlled by a program stored in memory 86and which takes over the subsequent processing.

The advantage of utilizing the upstream comparison stage is thatmicroprocessor 85 is only fed the signal after it has first beenestablished that the specific receiving device has been addressed.

Timer 84 controls the timing for the receiver unit.

The data derived from the received signal as well as any additional dataas possibly required is shown to the user on display 87. Display 87 isarranged behind a transparent section of the wall of receiver unit 2housing 70. The display shows the currently prevailing transmissiontorque and, if required, turbine temperature as well.

The respective data remains visible on the display until a newmeasurement is carried out and a transmission of the values establishesnew data.

The receiving device furthermore comprises a circuit means 88 (shownhere only in schematic representation) having the previously mentionedswitch 73.

The actual process of the allocating or the pairing of the transmitterunit and the receiver unit during the address change mode will now bedescribed in the following.

As previously stated, each transmitter unit is assigned its own uniqueaddress signal during manufacture, one which is commissioned only once.A 24 bit signal is utilized in the present embodiment, which yields atotal of 16.7 million different addressing possibilities. This highnumber ensures that no two transmitter units will ever have the sameidentical signal.

The address signal of the transmitter unit is filed in a constant memoryarea of memory 23 of transmitter unit 2. It is also possible to storethe address signal in a RAM memory area; however, in this case thesignal must additionally be otherwise locatable in the device, e.g. by aconcurrent utilization of its manufacturer number or the like so thatthe signal can be read correctly again following a battery replacement.

The address change mode is started each time the transmitter unit putinto operation. As previously explained, this transpires preferably bymeans of a predefined stipulated activation criterion, for example thestarting of the helicopter. The transmitter unit then changes to addresschange mode and sends a signal, as represented in FIG. 6, which iscomprised of a preamble, an address control signal, the actual addresssignal and a postamble. In the embodiment shown, the preamble is 16 bitslong, the postamble is 4 bits long, an d both the address control signalas well as the actual address signal are each 24 bits long.

The address control signal is recognized by all receiver units of thecorresponding series. As soon as a receiver unit receives this signal,the microprocessor induces a switching over to address change mode. Theprocessor then queries on the display whether the address signal of thetransmitter unit is to be accepted. Following actuation of switch 73 ofcircuit means 88, thus confirming said acceptance to the processor, theaddress signal of the transmitter unit is appropriated and saved as theaddress comparison signal in memory 86.

The control program of the receiver unit stored in memory 86 can beconfigured such that the receiver unit, as soon as it receives thetransmitter unit's address control signal in address change mode,analyzes whether the address comparison signal it has on file concurswith the transmitter unit's address signal. Should this be the case, thereceiver unit can then show that it is set to said transmitter unit sothat the user knows the two devices are allocated to one another.

In order to prevent an inadvertent allocation of devices, the addresschange mode of the embodiment comprises several security steps.

The first security step is the coupling of the beginning of the addresschange mode with the transmitter unit activation criterion. Addresschange will only ever ensue as a direct result of occurrence of theactivation criterion, thus reliably preventing that an address changewill start during the normal operation of the device.

At a second security step, a corresponding device in the receiver unitperforms a measurement of the energy of the signal received in addresschange mode. The receiver unit's program is configured such thatwhenever an address control signal is received, an energy measurement ofthe aggregate signal is carried out. An allocation is then only possiblewhen the transmission energy exceeds a certain limit.

As is known, transmission of energy from transmitter to receiver unit iscontingent upon distance and, to a considerable degree, also upon therespective alignment of both antennas to one another. Only when thedevices are arranged in a certain manner to one another with respect tospatial and angle contingencies will the energy received by the receiverunit be at a maximum high. The critical threshold value for the energymeasurement is thus to be selected such that an allocation may onlytranspire when the transmitter unit and the receiver unit are not onlyarranged at a short distance from one another, but are also align ed ata predetermined angle from one another.

In order to facilitate the angle-contingent allocation, the antennas ofthe transmitter unit and the receiver unit are preferably arranged intheir respective housings such that maximum energy is yielded upon aparallel or T-shaped arrangement of the devices to one another.

In order to also exclude fortuity at this stage as well, the emitting ofthe address control signal is repeated several times, but does notproceed to sufficient signal energy until the measured value of aspecific proportional percentage of the transmission registers above thecritical limit.

Finally, and this represents the next security step, the user is stillrequired to confirm the address change by actuating circuit means 88.

An allocation thus transpires only when:

1. receiver unit and transmitter unit are basically arranged directlyadjacent one another at a defined angle;

2. the helicopter is started while in this state, and

3. the identification is manually activated b the user.

Contingent upon the measured torque, microprocessor 85 feeds a signal,to the warning device.

In the preferred embodiment as represented, warning means 5 is firmlyconnected to the housing of receiver unit 70. Beginning at a predefinedfirst torque limit, processor 85 feeds a signal to warning means 5, saidsignal becoming stronger as the measured torque becomes greater.

Correlated to the magnitude of the signal which warning means 5 receivesfrom processor 85, warning means 5 generates vibrations which aretransmitted to housing 70 of the receiver unit and consequently to thearm of the user. The user will also register the receiver unitvibrations on his wrist even if he is distracted with other sensoryinput such as conversations with the tower or other difficult tasks.Hence, the user receives a reliable warning of transmission overload.

REFERENCE NUMERAL LIST

1 Warning device

2 Transmitter unit

3 Receiver unit

4 Display means

5 Warning means

7 Torque sensor

10 Housing

13 Battery

20 Signal processing circuit

21 Transmitting device timer

22 Microprocessor CPU

23 Memory

25 Transmission output stage

26 Antenna

40 Time axis

41 Time segment

43 Time segment

45 Time segment

46 Measurement interval

47 Transmission interval

49 Time segment

60 Diagram

61 Time axis

62 Numerical axis

64 Diagram

65 Time axis

66 Voltage axis

67 Voltage signal

70 Receiver unit housing

71 Battery

73 Switch

80 Ferrite antenna

81 Signal processing and amplifying stage

82 Digitalizing stage

83 Comparator

84 Timer

85 Microprocessor

86 Memory

What is claimed is:
 1. Warning device for indicating dangerouscircumstances, especially for helicopters, having: a transmitter forreceiving and processing an operational status signal; a signalcomparison means which compares the received operational status signalagainst predefined criterion; a signal generating means which generatesa monitoring signal when said operational status signal meets saidcriterion and an address signal uniquely identifying said transmitter; asignal transmitting means which wirelessly emits an emitted signalcomprising said generated monitoring signal and said address signal; asignal receiving means which receives said emitted signal; a receivercomparison means which analyzes whether said received monitoring signalmeets predefined monitoring signal criteria; an output means which emitsan output signal when said monitoring signal meets said criteria;whereby said receiving means, said receiver comparison means and saidoutput means are worn by a user and said output signal is immediatelyperceived by the user; said output means further comprising a memorystoring an address comparison signal and an address comparison meanswhich analyses whether the received address signal concurs with theaddress comparison signal stored in memory; at least one of said addresssignal and said address comparison signal being variable; signalchanging means capable of changing said one of said address signal andsaid address comparison signal to make said address signal and saidaddress comparison signal identical to one another; said output meansonly emitting said output signal when the address signal received bysaid output means and the address comparison signal stored in the memoryare identical.
 2. Warning device for indicating dangerous circumstancesaccording to claim 1, characterized in that said output means comprisesa display means for displaying the operational status.
 3. Warning devicefor indicating dangerous circumstances according to claim 1,characterized in that a conversion means is provided which digitallycodes the emitted signal to be transmitted by said signal transmittingmeans.
 4. Warning device for indicating dangerous circumstancesaccording to claim 1, characterized in that at least said signalgenerating means of said signal transmitting means comprises a firstmicroprocessor means which is controlled by a program filed in a memory.5. Warning device for indicating dangerous circumstances according toclaim 1, characterized in that said output means comprises amicroprocessor unit which is controlled by a program stored in thememory allocated to said output means.
 6. Warning device for indicatingdangerous circumstances according to claim 1, characterized in that saidaddress signal is stored in the signal transmitting means as a digitalsequence of numbers having n bits and that the address comparison signalis likewise stored in the memory as a digital sequence of numbers havingn bits.
 7. Warning device for indicating dangerous circumstancesaccording to claim 1, characterized in that the signal generating meansof said signal transmitting means generates an address control signal;that an address control comparison signal is stored in the memory of theoutput means; and that the receiver comparison means switches saidoutput means to an address signal change mode as soon as the comparisonmeans recognizes that an address control signal emitted by themonitoring transmission signal transmitting means is identical to theaddress control comparison signal stored in the output means.
 8. Warningdevice for indicating dangerous circumstances according to claim 7,characterized in that said signal transmitting means comprises a firstdetection means which recognizes the occurrence of a predefinedcriterion and induces the switching of the signal transmitting means toan address change mode in which an address control signal and theaddress signal are emitted.
 9. Warning device for indicating dangerouscircumstances according to claim 1, characterized in that said outputmeans comprises a received energy measurement means which measures theenergy of the emitted signal received by the signal receiving means atleast upon instance of the signal comparison means establishing thatsaid address signal transmitted by the signal transmitting means isidentical with the address control comparison signal stored in theoutput means.
 10. Warning device for indicating dangerous circumstancesaccording to claim 1, characterized in that said signal changing meanscomprises a manually actuatable circuit means and that said addresssignal received during address change mode will only be filed in theoutput means when said manually actuatable circuit means is activated.11. Warning device for indicating dangerous circumstances according toclaim 1, characterized in that said signal changing means only changessaid one of said address signal and said address comparison signal whenthe energy of the received signal is above a predetermined defined valueand when said circuit means is activated.
 12. Warning device forindicating dangerous circumstances according to claim 1, characterizedin that transmission of the emitted signal from the signal transmittingmeans to signal receiving means transpires by means of ultrasound. 13.Warning device for indicating dangerous circumstances according to claim1, characterized in that transmission of the emitted signal from thesignal transmitting means to the signal receiving means transpires bymeans of electromagnetic waves.
 14. Warning device for indicatingdangerous circumstances according to claim 12, characterized in thattransmission of the emitted signal transpires via the change in phasingof a sinusoidal wave (phase shift keying).
 15. Warning device forindicating dangerous circumstances according to claim 1, characterizedin that said signal transmitting means comprises a timer unit andmeasures status at predefined set intervals of time.
 16. Warning devicefor indicating dangerous circumstances according to claim 15,characterized in that the status determined during a measurement isconverted into a signal and transmitted prior to the next measurementbeing performed and that a programmed intelligent sequence is providedwhich effects that the temporal interval between measurement andtransmission of measured signals is not constant.
 17. Warning device forindicating dangerous circumstances according to claim 1, characterizedin that said warning device monitors at least one of the criticaloperating parameters of the system to be monitored.
 18. Warning devicefor indicating dangerous circumstances according to claim 1,characterized in that a warning signal is triggered in the event thatone of said critical operating parameters monitored exceeds apredetermined threshold.
 19. Warning device for indicating dangerouscircumstances according claim 18, characterized in that the intensity ofsaid warning signal is contingent upon the exceeding of said threshold.20. Warning device for indicating dangerous circumstances according toclaim 17, characterized in that the decisive torque parameter respectivetransmission overload is defined and monitored.
 21. Warning device forindicating dangerous circumstances according to claim 17, characterizedin that the decisive temperature parameter respective turbine overloadis defined and monitored.
 22. Warning device for indicating dangerouscircumstances according to claim 18, characterized in that said outputmeans generates vibration upon the generating of said warning signal.23. Warning device for indicating dangerous circumstances according toclaim 18, characterized in that said output means generates aphysiologically harmless electric pulse upon the emitting of saidwarning signal.
 24. Warning device for indicating dangerouscircumstances according to claim 18, characterized in that said outputmeans generates a physiologically tolerable amount of heat for beingperceived by the user upon the emitting of said warning signal. 25.Warning device for indicating dangerous circumstances according to claim1, characterized in that said output means emits a warning signal bymeans of activating warning lights.
 26. Warning device for indicatingdangerous circumstances according to claim 25, characterized in thatseveral warning lights are provided and that the number of warninglights which are lighted is a measure of an operational parameterapproaching a dangerous state.
 27. Warning device for indicatingdangerous circumstances according to claim 1, characterized in that saidsignal receiving means, said receiver signal comparison means and saidoutput means are arranged within one housing.
 28. Warning device forindicating dangerous circumstances according to claim 27, characterizedin that said housing with said monitoring transmission signal receiverunit of the warning device is capable of being worn at the user's wristby means of a strap.
 29. Warning device for indicating dangerouscircumstances according to claim 28, characterized in that saidmonitoring transmission signal receiving means and said output means areintegrated in one wristwatch.
 30. Warning device for indicatingdangerous circumstances according to claim 1, characterized in that saidsignal receiving means and said output means are arranged on the frameof a pair of glasses.
 31. Warning device for indicating dangerouscircumstances according to claim 1, characterized in that said warningdevice monitors the critical operational parameters of a helicopter. 32.Warning device for indicating dangerous circumstances according to claim1, characterized in that said warning device monitors the criticaloperational parameters of an aircraft.
 33. Warning device for indicatingdangerous circumstances according to claim 1, characterized in that saidwarning device monitors the critical operational parameters of a motorvehicle.
 34. Warning device for indicating dangerous circumstancesaccording to claim 12, characterized in that transmission of the emittedsignal transpires via a differential change in phasing (differentialphase shift keying).
 35. Warning device for indicating dangerouscircumstances according to claim 13, characterized in that transmissionof the emitted signal from the signal transmitting means to the signalreceiving means transpires by means of radio waves.